* international/mule.el (optimize-char-coding-system-table):

Remove this function.
(register-char-codings): Make it obsolete.
(char-coding-system-table): Defconst it here.
(make-coding-system): Don't call register-char-codings, call
define-coding-system-internal.

1 files changed, 11 insertions, 77 deletions

diff --git a/lisp/international/mule.el b/lisp/international/mule.el
index 9ba35cd32b9..d5e516ee059 100644
--- a/lisp/international/mule.el
+++ b/lisp/international/mule.el
@@ -592,83 +592,16 @@ character code range.  Thus FUNC should iterate over [START, END]."
                  (make-char charset (+ i start) start)
                  (make-char charset (+ i start) (+ start chars -1)))))))
 
-(defun optimize-char-coding-system-table ()
-  "Optimize `char-coding-system-table'.
-Elements which compare `equal' are modified to share the same list."
-  (let (cache)
-    (map-char-table
-     (lambda (k v)
-       ;; This doesn't worry about elements which are permutations of
-       ;; each other.  As it is, with utf-translate-cjk on and
-       ;; code-pages loaded, the table has ~50k elements, which are
-       ;; reduced to ~1k.  (`optimize-char-table' might win if
-       ;; permutations were eliminated, but that's probably a small
-       ;; effect and not easy to test.)
-       (if v
-           (let ((existing (car (member v cache))))
-             (if existing
-                 (aset char-coding-system-table k existing)
-               (push v cache)))))
-     char-coding-system-table))
-  (optimize-char-table char-coding-system-table))
-
 (defun register-char-codings (coding-system safe-chars)
-  "Add entries for CODING-SYSTEM to `char-coding-system-table'.
-If SAFE-CHARS is a char-table, its non-nil entries specify characters
-which CODING-SYSTEM encodes safely.  If SAFE-CHARS is t, register
-CODING-SYSTEM as a general one which can encode all characters."
-  (let ((general (char-table-extra-slot char-coding-system-table 0))
-        ;; Charsets which have some members in the table, but not all
-        ;; of them (i.e. not just a generic character):
-        (partials (char-table-extra-slot char-coding-system-table 1)))
-    (if (eq safe-chars t)
-        (or (memq coding-system general)
-            (set-char-table-extra-slot char-coding-system-table 0
-                                       (cons coding-system general)))
-      (map-char-table
-       (lambda (key val)
-         (if (and (>= key 128) val)
-             (let ((codings (aref char-coding-system-table key))
-                   (charset (char-charset key)))
-               (unless (memq coding-system codings)
-                 (if (and (generic-char-p key)
-                          (memq charset partials))
-                     ;; The generic char would clobber individual
-                     ;; entries already in the table.  First save the
-                     ;; separate existing entries for all chars of the
-                     ;; charset (with the generic entry added, if
-                     ;; necessary).
-                     (let (entry existing)
-                       (map-charset-chars
-                        (lambda (start end)
-                          (while (<= start end)
-                            (setq entry (aref char-coding-system-table start))
-                            (when entry
-                              (push (cons
-                                     start
-                                     (if (memq coding-system entry)
-                                         entry
-                                       (cons coding-system entry)))
-                                    existing))
-                            (setq start (1+ start))))
-                        charset)
-                       ;; Update the generic entry.
-                       (aset char-coding-system-table key
-                             (cons coding-system codings))
-                       ;; Override with the saved entries.
-                       (dolist (elt existing)
-                         (aset char-coding-system-table (car elt) (cdr elt))))
-                   (aset char-coding-system-table key
-                         (cons coding-system codings))
-                   (unless (or (memq charset partials)
-                               (generic-char-p key))
-                     (push charset partials)))))))
-       safe-chars)
-      ;; This is probably too expensive (e.g. multiple calls in
-      ;; ucs-tables), and only really relevant in certain cases, so do
-      ;; it explicitly where appropriate.
-      ;; (optimize-char-coding-system-table)
-      (set-char-table-extra-slot char-coding-system-table 1 partials))))
+  "This is an obsolete function.  
+It exists just for backward compatibility, and it does nothing.")
+(make-obsolete 'register-char-codings
+               "Unnecessary function.  Calling it has no effect."
+               "21.3")
+
+(defconst char-coding-system-table nil
+  "This is an obsolete variable.
+It exists just for backward compatibility, and the value is always nil.")
 
 (defun make-subsidiary-coding-system (coding-system)
   "Make subsidiary coding systems (eol-type variants) of CODING-SYSTEM."
@@ -1088,7 +1021,6 @@ a value of `safe-charsets' in PLIST."
                 (if (and (symbolp val)
                          (get val 'translation-table))
                     (setq safe-chars (get val 'translation-table)))
-                (register-char-codings coding-system safe-chars)
                 (setq val safe-chars)))
           (plist-put plist prop val)))
       ;; The property `coding-category' may have been set differently
@@ -1122,6 +1054,8 @@ a value of `safe-charsets' in PLIST."
                (error "Invalid EOL-TYPE spec:%S" eol-type))))
   (put coding-system 'eol-type eol-type)
 
+  (define-coding-system-internal coding-system)
+
   ;; At last, register CODING-SYSTEM in `coding-system-list' and
   ;; `coding-system-alist'.
   (add-to-coding-system-list coding-system)